This invention relates to apparatus for applying surgical fasteners to body tissue, and more particularly to apparatus for applying a relatively large number of such fasteners substantially simultaneously.
Instruments for applying relatively large numbers of surgical fasteners simultaneously or substantially simultaneously are known as shown, for example, by Hirsch et al. U.S. Pat. No. 3,275,211, Green U.S. Pat. No. 4,402,444, and Green U.S. Pat. No. 4,402,445. The fasteners may take the form of metal surgical staples as shown in the Hirsch et al. patent, or they may be initially two-part non-metallic surgical fasteners as shown in the Green U.S. Pat. No. 4,402,445. The term "surgical fasteners" is used herein as a generic term for both of these types of fasteners.
Some surgical procedures require the application of a very large number of surgical fasteners. For example, the device shown in the Green U.S. Pat. No. 4,402,444 is adapted to apply 50, 60, or even more fasteners in four closely spaced rows. If all of these fasteners are driven exactly simultaneously, the peak force required can be very large. This necessitates an instrument design which is very strong and correspondingly costly. It also may make this instrument relatively difficult to operate.
It is therefore an object of this invention to reduce the peak force required in instruments which apply relatively large numbers of surgical fasteners.